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LandNav - Why know your pace?

While pace counting is admittedly an arcane distance determination technique that is seldom used by trail-bound hikers, it is an essential technique used by advanced-level land navigators who travel cross-country through challenging wilderness. In certain situations, a map and compass alone just aren't enough.

Pace counting is an ancient technique. Legionnaires in the Roman Army used it on the battlefield just as today's warriors do. Ranger pacing beads were widely used in Vietnam and continue to be popular. Sure, the GPS is the go-to nav tool, but when batteries die or the device fails, those old land-nav skills are the answer.

Our English statute mile is based on the Roman soldier's mile. The Latin phrases "mille passus," or "milia passuum," which meant a "thousand paces," were eventually shortened to a "mile" in English. The average soldier laid down 5,000 "foot-lengths" or "feet" in a mile. Much like the pace we use today, a Roman pace consisted of two steps equalling about 5 "foot-lengths."

WHY COUNT PACES?

While pace counting is admittedly an arcane distance determination technique that is seldom used by trail-bound hikers, it is an essential technique used by advanced-level land navigators who travel cross-country through challenging wilderness. In certain situations, a map and compass alone just aren't enough.

In his book, entitled "Orienteering," John Disley writes that "more mistakes are made in orienteering by wrongly estimating distance than from any other reason." While most of us can quickly learn to travel in the right direction, few of us have any idea of how far we have traveled.Think about Disley's observation for a moment. Have you ever cut an azimuth through the bush and wondered if you had missed your target, or perhaps not gone far enough, when it did not materialize? Did you continue on another 10 minutes, then 20 minutes, hoping it would appear? Or did you backtrack? You could have eliminated much of the guesswork in this situation by using a technique known as "step-counting."Pace counting with Ranger pacing beads is well suited for the complicated navigational challenges faced by today's wilderness navigator. For example, pace counting is essential for dead reckoning, where azimuth (or direction of travel) data is combined with pacing (or distance traveled) data. With this technique, you can establish your position in plain terrain, foul weather, or even in complete darkness. FYI the "dead" in dead reckoning is derived from "ded.," an abbreviation of "deduced." Its navigation by deduction.

USING RANGER BEADS

For the purposes of pace counting, a pace is defined the distance between two foot-strikes of the right foot. In other words, a pace is counted each time the right foot strikes the ground, not each time the right and the left foot strikes the ground.

To use pacing beads configured for the metric measurement system, the average adult male traveling on a flat, open trail can simply count the number of times his right foot hits the ground and pull a lower 100-meter march bead every 66 paces, which should equal 100 meters, assuming his pace is about 1.5 meters long. The number of paces necessary to cover 100 meters for other pace lengths can be determined by referring to the chart below.

When no lower 100-meter march beads remain to be pulled, simply pull down an upper klick bead, which represents 1000 meters of travel, and then reset the 100-meter march beads by sliding all 9 back up.

Using pacing beads configured for the English measurement system is equally simple. The only difference is that when you reach to pull down the eighth march bead, which does not exist, simply pull an upper half-mile bead, resetting the lower march beads to begin counting into the next half-mile segment. This setup will allow you to keep track of up to 3.5 miles worth of pacing.

If you find you must make a lateral move to avoid a natural barrier or obstruction--be it a swamp, cliff, or lake--always stop your forward pace counting and side step to one side at a right angle to your original azimuth. When you've laterally cleared the obstacle, continue counting paces as you walk parallel to your original azimuth route. Once you're beyond the obstacle, remember to stop counting paces and side step, at a right angle, an equal number of paces back to your original line of travel. Begin counting paces again when you resume travel on your original azimuth.

Jamie Smith, former CIA Officer and founding Director of Blackwater Security suggests trying to avoid walking directly behind or abreast of another hiker as their pace may influence your rhythm and throw off the accuracy of your pacing. Each time you come upon a known landmark, which you can confirm on your map, re-start your pacing counting to ensure maximum accuracy. When traversing known distances, take advantage of the opportunity to check the accuracy of your pace counting as well as your rate of travel (minutes per klick).With practice, pace counting will become nothing more than a subconscious, background activity that will greatly increase your land navigation abilities.

FIGURING YOUR PACE

One of the easiest ways to calculate your pace in the field is to simply mark the location where your right toe (or heel) strikes the ground several times in a row and then measure the distance between the strike marks to come up with a good average. If you've measured your boot length prior to the trip, you can use your boot in a heel-to-toe fashion to determine your pace length. Always calculate your pace with a loaded rucksack in the bush you are about to traverse.

Once you know how long your pace is, consult the table below to determine how many paces to count before pulling a 100-meter (or 110-yard) march bead. While the march-bead pace figures in the table below are in meters, they'll work equally well with the English measurement system since 100 meters equals 110 yards.

Always verify your pace length at the start of a trip as well as whenever the terrain, rucksack load, or another factor affecting your pace length changes. Once fully mastered, allow for at least a 10 percent error rate on flat open terrain.

Hilly terrain will require you to alter your pace counting some, possibly skipping the counting of every third pace. You could also recalculate the horizontal distance advanced for each pace and then use a higher pace count for each 100-meter up - or down-hill march.

Keep in mind that distances measured on a two-dimensional map account for horizontal change only--they assume the terrain is flat. On the other hand, your in-the-field pacing measurements over the same terrain may be longer if the area is hilly since your pacing will take into account both vertical and horizontal influences.